Cannabis is a drug produced from the Cannabis sativa or Cannabis indica plant. It contains over 400 chemicals including THC which is the main psychoactive ingredient. Cannabis is most widely used as an illegal recreational drug for its relaxing effects, but it also has some medical uses such as reducing nausea from chemotherapy and muscle spasticity in MS patients. However, cannabis use can also have health risks like impaired concentration and coordination, increased risk of psychosis, and potential for dependence.

1. What is cannabis?
Cannabis is a drug produced from the Cannabis sativa (commonly known as hemp)
or Cannabis indica plant, which is related to nettles and hops. It's believed to have
originated in the mountainous regions of India, and grows wild in many parts of the
world.
The plant contains more than 400 chemicals, including cannabidiolic acid, an
antibiotic with similar properties to penicillin. The different chemical derivatives of
the plant can be used for medicinal or recreational purposes.
The recreational drug cannabis comes in many forms – herbal (dried plant
material), resin, powder and oil - and is known by many slang terms,
including weed, pot, grass and hash. In the UK, cannabis is a Class B
illegal drug.
Effects and uses of cannabis
Cannabis is most widely used as a illegal street drug for its relaxing properties. It is
usually rolled into a cigarette known as a joint, but can also be smoked in a pipe,
brewed as a tea or mixed with food.
The main active ingredient in cannabis is tetrahydrocannabino (THC). One type,
skunk, can be particularly potent as it contains two to three time as much THC as
other types.
Cannabis acts as a mild sedative, leaving most people feeling relaxed, chilled out or
just sleepy. It also:
• Has mild hallucinogenic effects, causing a distortion of reality
• Makes some people become more animated
• Releases inhibitions, making people talkative or giggly
• Can cause nausea in some people (despite the fact that cannabis can have an
anti-nausea effect), while it quite often makes others feel hungry
Medical uses of cannabis
Cannabis or its derivatives may also be used as a medical treatment. There is some
scientific evidence to suggest it may be useful in a wide range of conditions. But the
complex nature of the substances contained within the plant makes it difficult for
medical research to establish the safety or efficacy in its natural form, so its effects
are far from proven or well-understood. As scientists are interested in the possible
therapeutic properties of cannabis, they are working to gradually identify the active

2. chemicals within (these chemicals are known collectively as cannabinoids).
Cannabinoids activate a number of receptors throughout the body but especially in
the central nervous system and the immune system, and so may have several
effects.
Wide-scale trials testing the safety and efficacy of these cannabis extracts (or
synthetic forms of them) are currently underway in the UK and elsewhere. So far
there has been interest in the use of cannabinoids in nausea and vomiting, appetite,
control of cancer symptoms, pain, anxiety and muscle spasticity.
For instance, cannabis appears to be able to help reduce the side effects of
chemotherapy treatment, although not more so than other already established
medications. The drugs used to treat cancer are among the most powerful, and most
toxic, used in medicine. They produce unpleasant side effects, such as days or weeks
of vomiting and nausea after each treatment. Some cannabinoids relieve nausea and
allow patients to eat and live normally.
Cannabis extracts also seem to benefit people suffering from multiple sclerosis (MS),
by reducing muscle spasticity and so increasing their ability to stay independent. The
first cannabinoid medicine derived from whole plant extracts (from the cannabis
sativa plant) came into use in the UK in 2010 for people with moderate to severe
spasticity in MS who haven't responded to other treatments. Unlike recreational
cannabis, this treatment doesn't cause euphoria - less than 3% of those in trials for
the drug said it changed their mood.
Claims have also been made for its use in treating:
• Migraine
• Headaches
• Asthma
• Strokes
• Parkinson's disease
• Alzheimer's disease
• Alcoholism
InsomniaRisks of cannabis
There's increasing evidence that cannabis use is linked to a number of health risks. It
damages the ability to concentrate, decreases motivation and more than occasional
use in teenagers can affect psychological development. Users can become anxious,

3. suspicious and even paranoid. Heavy use increases the risk of serious psychiatric
illness.
Users of skunk, a stronger and increasingly more available form of cannabis, are
seven times more likely to develop a psychotic illness, such as schizophrenia, than
people not using cannabis or using the more traditional forms. Cannabis also
interferes with coordination, causing problems with balance, walking and driving.
There are other side effects of the drug, but they vary considerably and are less
predictable, partly because cannabis has more than 400 active ingredients. They
may include effects on the heart, such as increased heart rate and blood pressure,
and damage to fertility. People who smoke cannabis are also exposed to the toxic
chemicals in tobacco smoke.
People may become dependent on cannabis and find it difficult to stop using it,
experiencing unpleasant withdrawal symptoms if they do stop such as cravings,
agitation, mood changes, sleep problems, appetite disturbance and other symptoms.
The debate over the use of cannabis in medicine is highly controversial and emotive.
Supporters of the drug claim it has wide-ranging benefits, but opponents say it is a
potentially dangerous substance that can actually damage health.
Cannabis and the law
The use of cannabis remains illegal (except for prescribed cannabinoids as described
above). It is a Class B drug. As a result, the penalties for getting caught with
cannabis, especially on repeated occasions, can be severe. The maximum penalty for
possession is 5 years in prison and for supplying the drug, 14 years, although an
initial reprimand or penalty fine may be given for first-time offenders.
A report by the House of Lords Science and Technology Committee in 1997
recommended the use of cannabis for medicinal purposes. However, the British
Medical Association (BMA) did not give the report tis full support and believes only
cannabinoids - carefully identified chemical derivatives of the cannabis plant - should
be used in medicine.
Advice and support
Occasional users of cannabis may be able to give it up, although they may find it
harder to give up the general smoking habit. However, heavier users may need
expert help to stop. Talk to your GP or local community drug agency or clinic.

4. www.bbc.co.uk/health/emotional_health/addictions/cannabis.shtml